Device for inspecting a weld of a hollow longitudinal tubular element

Abstract

The invention concerns a device (10) for inspecting a weld of a hollow longitudinal tubular element, comprising: - a frame (12), - a system (14) for hooking and locking said frame on the tubular element, - a movable member (19) connected to the frame (12) and rotatable with respect to the frame (12) about the tubular element, - a device (20) for rotating the movable member (19) with respect to the chassis (12), - a support (29) including at least one sensor block (24) for sensing Foucault currents connected to the movable member (19), the support (29) being movable in longitudinal translation with respect to the movable member (19), - a device (26) for driving the support (29) in longitudinal translation.

Description

[0001] The present invention relates, in a first aspect, to a device for controlling a weld of a hollow longitudinal tubular element.

[0002] More specifically, the invention relates to a device for controlling a weld of a tubular element from the outside.

[0003] For example, the invention relates to a weld control device for pipes or piping lines that enable the taking of physical measurements (flow rate, pressure) of the primary circuit of a nuclear reactor. These pipes, also called "tubing" in English, are located in the reactor building. They have a small outside diameter.

[0004] For example, when replacing a steam generator in a nuclear reactor, some of the pipes directly connected to the steam generator must also be replaced. Once the steam generator has been replaced, it is therefore necessary to inspect the welds on these pipes.

[0005] To achieve this, a known method is to use a radiographic inspection device for welds, employing photographic film and a radioactive source, such as iridium-192. These inspections are lengthy and tedious. This technique also involves a significant number of handling operations with radioactive sources. The chemicals used for film development must also undergo specific treatments. Furthermore, the operating conditions require personnel trained in radiation protection. Finally, this technique does not provide real-time results.

[0006] US 8 141 442 B2 describes an example of an eddy current scanner capable of moving axially along a pipe.

[0007] FR 3 069 060 A1 also describes an inspection tool which includes an eddy current probe and which allows a metal tube to be inspected in order to detect any surface defects.

[0008] WO 2017 / 124194 A1 describes a tape and an ultrasound scanner for inspecting circumferential pipeline welds. The tape and the ultrasound scanner are designed to orient the elements in the defined radial direction relative to the pipeline, thereby reducing the overall size of the assembly.

[0009] One objective of the invention is to provide a control device that allows for precise, reliable, non-destructive, easy and rapid control of a hollow tubular element, and that is particularly suitable for the nuclear environment.

[0010] For this purpose, the invention relates to a control device according to claim 1.

[0011] Such a system allows for shorter inspection times and real-time interpretation of results. The handling of chemicals and radioactive sources is avoided, significantly reducing the risks associated with inspection operations. Finally, the absence of radioactive sources allows for concurrent activities on the site where the inspections are taking place.

[0012] According to particular embodiments, the control device comprises one or more of the features of dependent claims 2 to 7.

[0013] The invention relates, according to a second aspect, to a method for checking a weld of a hollow longitudinal tubular element according to claim 8.

[0014] According to a particular embodiment, the process according to the invention may include the feature of claim 9.

[0015] Other features and advantages of the invention will become apparent from the following description, given solely by way of example and with reference to the accompanying drawings, including: [ Fig 1 ] there figure 1 is a general perspective view of a control device according to the invention; [ Fig 2 ] there figure 2 is a more detailed perspective view of the rotational drive mechanism of the moving part of the control device figure 1 ; Fig 3 ] there figure 3 is a detailed perspective view of the longitudinal translation drive mechanism of the control device support. figure 1 ; And [ Fig 4 ] there figure 4 is a detailed perspective view of the rotational drive mechanism of the moving part cooperating with the longitudinal translational drive mechanism of the control device support. figure 1 .

[0016] A control device 10 for a weld on a hollow longitudinal tubular element (not shown) according to the invention is illustrated in the figure 1 .

[0017] The hollow tubular element is, for example, a thin-walled austenitic stainless steel pipe found in a nuclear power plant reactor building.

[0018] The external diameter of the tubular element is, for example, between 8 mm and 20 mm. Preferably, the external diameter of the tubular element is around 9.5 mm. The wall thickness of the tubular element is less than 2 mm and is preferably around 1.65 mm.

[0019] The small dimensions (diameter, thickness) of the tubular element allow both surface and volumetric controls.

[0020] In general, both types of control, surface and volumetric, are likely to be carried out on the pipes present in the reactor building.

[0021] The weld is typically a butt weld between two hollow tubular elements.

[0022] The control device 10 comprises a chassis 12 and a fastening and locking system 14 for said chassis 12 on the tubular element visible more particularly on the figure 1 .

[0023] The hooking and locking system 14 is movable between an open position in which the tubular element is not held in the control device 10, and a closed position in which the tubular element is held in the control device 10.

[0024] The fastening and locking system 14 comprises a retaining member 16 and two connecting rods 18, fixed respectively at a first end 21 to the retaining member 16 and at a second end 22 to the frame 12. At the first end 21 of each connecting rod 18, the connecting rod 18 is free to rotate relative to the retaining member 16 about a first axis of rotation. At the second end 22 of each connecting rod 18, the connecting rod 18 is free to rotate relative to the frame 12 about a second axis of rotation substantially parallel to the first axis of rotation.

[0025] When the control device 10 is fixed on the hollow tubular element, the first and second axes of rotation are substantially parallel to the longitudinal direction of the hollow tubular element.

[0026] More specifically, the fastening and locking system 14 includes at least one retaining hook 23, for example two retaining hooks 23, as shown in the figure 1 The retaining hooks are fixed to the frame 12.

[0027] The retaining hooks 23 define a receiving housing 25 for the tubular element.

[0028] The retaining member 16 comprises respectively two fixing members 27 which cooperate with the retaining hooks 23 in the closed position.

[0029] Advantageously, each fastening member 27 has a shape complementary to that of the retaining hook 23. Thus, in the closed position, the tubular element is held in the receiving housing 25 defined by the retaining hook 23 and the fastening member 27 of the retaining member 16.

[0030] Thus, in operation, the hooking and locking system 14 allows the tubular element to be clamped in the control device 10.

[0031] Preferably, the fastening and locking system 14 includes, for example, at least one removable assembly member (not shown), for example a bolt, so as to fix the retaining member 16 on the chassis 12.

[0032] The fastening and locking system 14 keeps the control device 10 firmly attached to the tubular element and prevents accidental movement of the device 10 during measurement operations. This helps improve the reliability and accuracy of measurements taken on the tubular element.

[0033] Most notably visible on the figure 2 , the control device 10 includes a moving part 19 linked to the chassis 12, a rotational drive device 20 of the moving part 19 relative to the chassis 12, a support 29 comprising at least one eddy current sensor block 24 linked to the moving part 19, and a longitudinal translational drive device 26 of said support 29.

[0034] The movable part 19 includes a cylindrical sleeve 28 adapted to surround the tubular element. When the control device 10 is fixed to the tubular element, the cylindrical sleeve 28 extends substantially along the longitudinal direction of the tubular element.

[0035] The cylindrical sleeve 28 is mounted to slide on an inner face of the retaining hook 23.

[0036] The movable part 19 is free to rotate relative to the frame 12 around the tubular element. More specifically, when the control device 10 is fixed to the tubular element, the axis of rotation of the movable part 19 is substantially coincident with the longitudinal axis of the tubular element.

[0037] Advantageously, the movable part 19 is rotationally movable around the tubular element between a plurality of positions. Preferably, the positions are discrete and stable.

[0038] The plurality of positions is for example between ten and twenty-four, for example twenty-one.

[0039] For example, the positions are regularly distributed angularly around the tube.

[0040] Preferably, the positions are distributed around the entire periphery of the tube.

[0041] Alternatively, the positions are distributed over a part of the periphery of the tube, for example over an angular distance of 180°.

[0042] Thus, as we will see in more detail in the description, each rotational movement of the moving organ 19 causes the movement of the support 29 comprising the eddy current sensor block 24 around the tubular element.

[0043] Preferably, the rotation drive device 20 is a manually mechanically driven device.

[0044] As can be seen most notably on the figure 2 , the rotational drive device 20 includes, for example, a gripping member 30 projecting from the frame 12 and fixed to a drive pinion 32. The gripping member 30 is, for example, located on a side wall 34 of the frame 12 to facilitate gripping by the user ( figure 1 ).

[0045] The rotational drive device 20 further comprises a plurality of pinions 36 cooperating with said drive pinion 32 and the moving member 19, and more particularly with a toothed ring 38 fixed on one end of the moving member 19.

[0046] The rotary drive device 20 enables the moving part 19 to be moved reliably and precisely. The rotary drive device 20 also ensures good repeatability and reproducibility of the position of the moving part 19 around the tubular element. Thus, when the moving part 19 occupies the last position of the plurality of positions, a further movement of the moving part 19 using the drive device 20 brings the moving part 19 back precisely into the first position of the plurality of positions.

[0047] The control device 10 advantageously includes a first indexing device (not shown) configured to determine an angular position of the moving part 19 around the tubular element.

[0048] Thus, at all times, the angular position of the moving part 19 around the tubular element is precisely known and indexed at each acquisition of the eddy current sensor block 24. This ensures the reconstruction of a precise and high-quality circumferential image of the tubular element.

[0049] The support 29 is mobile in longitudinal translation relative to the moving part 19.

[0050] On the other hand, the support 29 is rotationally linked to the moving part 19 around the tubular element.

[0051] Preferably, the support 29 is mobile in translation between a plurality of positions relative to the moving organ 19.

[0052] The positions are preferentially discrete and stable.

[0053] For example, the support 29 is mobile between a first extreme control position on the tubular element and a second extreme control position on the tubular element.

[0054] The distance between the first extreme control position and the second extreme control position is between 30 mm and 50 mm.

[0055] The support 29 is thus advantageously moved between a plurality of positions between the first extreme control position and the second extreme control position. At each position, a measurement is taken with the eddy current sensor block 24.

[0056] For example, support 29 is moved by a constant interval between the first extreme position and the second extreme control position.

[0057] The interval is, for example, equal to 0.1 mm.

[0058] For example, the positions are separated from each other by a constant step.

[0059] As seen in detail on the figures 3 And 4 , the longitudinal translation drive device 26 includes for example a cylindrical sleeve 40 surrounding the moving part 19 and a holding part including the eddy current sensor block 24.

[0060] The translational training device 26 cooperates with the support 29.

[0061] Thus, for example, the cylindrical sleeve 40 defines a circumferential groove 42 and the support 29 includes a slide 44 cooperating with the circumferential groove 42 of the cylindrical sleeve 40.

[0062] As seen on the figure 2 , the movable organ 19 defines a window 45 through which the slide 44 exits, cooperating with the circumferential groove 42.

[0063] The movable part 19 defines at the level of the window 45 a longitudinal slide for the support 29.

[0064] The cylindrical sleeve 40 is mounted to slide longitudinally on the moving part 19.

[0065] The cylindrical sleeve 40 also allows the moving part 19 to be guided in rotation.

[0066] More specifically, when the moving part 19 is rotating around the tube, the slide 44 moves in the circumferential groove 42.

[0067] In addition, the circumferential groove 42 cooperates with the slide 44 to drive the support 29 and therefore the eddy current sensor block 24 longitudinally.

[0068] Thus, the cylindrical sleeve 40 drives the support 29, which includes the eddy current sensor block 24, in longitudinal translation along the tubular element.

[0069] Preferably, the longitudinal translation drive device 26 of the support 29 is a manually mechanically driven device.

[0070] For example, the longitudinal translation drive device 26 further includes a gripping member 46 fixed to the cylindrical sleeve 40 and projecting from the frame 12 ( figure 1 ).

[0071] The control device 10 according to the invention preferably comprises a second indexing device (not shown) configured to determine a longitudinal position of the support 29 relative to the moving part 19.

[0072] Thus, at all times, the longitudinal position of the support 29 is precisely known and indexed with each acquisition of the eddy current sensor block 24. This ensures the reconstruction of a precise and high-quality image of the tubular element.

[0073] The eddy current sensor block 24 comprises a probe 48 having two orthogonal windings 50 with respect to each other and mounted on a ferrite cube 52 ( figure 3 ).

[0074] For example, windings 50 are powered in differential mode. The eddy current sensor block 24 is thus insensitive to the orientation of potential faults at the weld of the tubular element. During a measurement, the impedance variation of windings 50 is analyzed along the tubular element and all around it. This measurement allows for a two-dimensional mapping of the tubular element's weld. Analysis of this map makes it possible to detect any discontinuities at the weld.

[0075] The eddy current sensor block 24 advantageously includes a magnetic saturation device 54 to standardize the magnetic permeability of the weld.

[0076] For example, the magnetic saturation device 54 comprises two magnets 56 oriented in the same direction. The two magnets 56 are intended to be positioned on either side of the tubular element to be inspected, and more specifically at the weld.

[0077] Advantageously, the eddy current sensor block 24 further includes a holding device 58 for the probe 48 on the surface of the tubular element.

[0078] The retaining device 58 ensures that the probe 48 is always in contact with the surface of the tubular element and that of the weld even when the outer surface of the tubular element or the weld is irregular.

[0079] The control device 10 typically includes an acquisition unit (not shown) connected to the eddy current sensor block 24 and to the first and second indexing devices in order to control the measurements of the eddy current sensor block 24 to its position relative to the weld (angular position around the tubular element and longitudinal position along the tubular element).

[0080] Typically, the measurements are transferred to a processing unit (not shown), such as a microcomputer for processing. The transfer is, for example, wired.

[0081] A method for checking a weld of a hollow longitudinal tubular element using the checking device 10 described above will now be described.

[0082] First, the process includes a step of attaching and locking the chassis 12 of the control device 10 onto the tubular element, and more particularly at the weld to be inspected, using the attachment and locking device 14.

[0083] The method then includes, for example, a step consisting of moving the movable part 19 in rotation at least once relative to the frame 12 around the tubular element, using the rotational drive device 20, and / or moving the support 29 in longitudinal translation at least once relative to the movable part 19, along the tubular element. Thus, the eddy current sensor block 24 is moved to a position that corresponds to the first extreme control position.

[0084] A first measurement is carried out with the 24 eddy current sensor block using the acquisition unit.

[0085] The method preferably comprises, for a defined angular position, moving the support 29 in longitudinal translation through a plurality of successive longitudinal positions, from the first extreme control position to the second control position. Each longitudinal position is separated from the previous position by an interval.

[0086] A measurement is taken with the 24 eddy current sensor block for each of the longitudinal positions.

[0087] When the support 29 reaches the second extreme control position, the support 29 is moved by longitudinal translation to the first extreme control position in a single longitudinal translation.

[0088] The movable part 19 is then rotated relative to the frame around the tubular element. The support 29 is then again moved in longitudinal translation between the first extreme control position and the second extreme control position in the plurality of longitudinal positions, and a measurement is taken with the eddy current sensor block 24 for each of the positions, etc.

[0089] The movements of the support 29 and the moving part 19 are repeated until the eddy current sensor block 24 completes a full rotation around the tubular element. A full rotation means that the eddy current sensor block 24 returns to its initial angular position after completing the plurality of rotational movements.

[0090] Preferably, each measurement taken with the 24 eddy current sensor block is transferred to the acquisition unit and then to the processing unit. The processing unit is configured to reconstruct a two-dimensional map of the tubular element at the weld.

[0091] Thus, any discontinuity in the weld can be easily and precisely identified by the user.

[0092] The control device 10 according to the invention is accurate and reliable.

[0093] Furthermore, the dimensions of the control device 10 according to the invention are sufficiently small to allow the control of a tubular element in a difficult-to-access environment, such as near a wall. The device 10 is advantageously contained within a 70 mm cylinder occupying three-quarters of the circumference of the tubular element. The control device 10 according to the invention allows for both surface and volumetric control of the tubular element.

Claims

1. An inspection device (10) for a weld of a hollow longitudinal tubular element comprising: - a chassis (12), - a hooking and locking system (14) for said chassis on the tubular element, said system (14) being designed to prevent any movement of the device (10) on the tubular element, - a movable member (19) connected to the chassis (12) and rotatable relative to the chassis (12) around the tubular element, - a rotational drive device (20) for the movable member (19) relative to the chassis (12), - a support (29) including at least one sensor block (24) with eddy currents connected to the movable member (19), the support (29) being translatable in the longitudinal direction relative to the movable member (19) and connected in rotation to the movable member (19) around the tubular element. - a longitudinal translation drive device (26) for said support (29), wherein the longitudinal translation drive device (26) comprises a cylindrical sleeve (40) surrounding the movable member (19), the cylindrical sleeve (40) defining a circumferential groove (42), the support (29) comprising a slide (44) cooperating with the circumferential groove (42) of the cylindrical sleeve (40).

2. The inspection device (10) according to claim 1, wherein the movable member (19) comprises a cylindrical sleeve (28) adapted to surround the tubular element.

3. The inspection device (10) according to claim 1 or 2, wherein the rotational drive device (20) and / or the longitudinal translation drive device (26) are manually operated mechanical devices.

4. The inspection device (10) according to any one of claims 1 to 3, wherein the rotational drive device (20) of the movable member (19) comprises a gripping member (30) projecting from the chassis (12) and fixed to a drive pinion (32), and a plurality of pinions (36) cooperating with said drive pinion (32) and the movable member (19) so as to drive the movable member (19) in rotation relative to the chassis (12).

5. The inspection device (10) according to any one of claims 1 to 4, wherein the movable member (19) is rotatable around the tubular element between a plurality of positions, the plurality of positions being between ten and twenty-four.

6. The inspection device (10) according to any one of claims 1 to 5, further comprising at least one indexing device configured to determine a position of the movable member (19) around the tubular element.

7. The inspection device (10) according to any one of claims 1 to 6, wherein the support (29) is movable in longitudinal translation relative to the movable member (19) between a plurality of positions.

8. A method for inspecting a weld of a hollow longitudinal tubular element using an inspection device (10) according to any one of claims 1 to 7, the method comprising the following steps: - hooking and locking the chassis (12) on the tubular element using the hooking and locking device (14), - displacing the movable member (19) at least once in rotation relative to the chassis (12) around the tubular element in an angular position, using the rotational drive device (20) and / or displacing the support (29) at least once in longitudinal translation relative to the movable member (19) in a longitudinal position, along the tubular element, - acquiring a measurement using the sensor block (24) with eddy currents.

9. The method according to claim 8, comprising, for each angular position, successively displacing the support (29) in longitudinal translation along the tubular element in a plurality of longitudinal positions from a first end inspection position to a second end inspection position.

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